Hello all,

Last year I purchased a used 2007 Mini Cooper S which already had the rattle noise these cars are notorious for having. At the time, I wasn't aware what the noise was and ignorantly assumed it was some plastic part under the car that was loose and would rattle during start up.

A year later, I heard the rattle everytime I went to start the car and all the way until the engine was turned off. There also seemed to be a seperate sound which sounded like the valve lifters. Mini diagnosed the car and quoted $2100 for replacing the entire timing chain system (guide rails, tensioner, crank sprocket, and new bolts). The plastic piece from the upper guide rail broke off and fell into my oil pan. I decided to do the job myself.

A few weeks later, I go to start my car and the rattle noise is gone. Hooray! But I couldn't be excited for long as I ended up hearing that second noise. The engine sounds like a bunch of clicks underneath my valve cover. I'm fairly confident I set the timing perfectly as I used a flywheel and cam lock tool.

While diagnosing this knocking sound, I read on Promini that disconnecting the mechanical valve pump hose from the valve cover is one way to do it. I did this and started my car again. This time, the knocking sound went away.

Does anyone know what this knocking sound could still be? I'm aware these engines run loud, but I'm fairly confident this isn't a normal sound because my car didn't run like this when I purchased it. My car was low on oil before the job which led to breakage of the guide rails, and I also noticed some scoring on the cam shafts. Any help would be greatly appreciated!


- Raf Cooper

 

The knocking noise that goes away when you disconnect the mechanical vacuum pump line comes from the coupler that connects the pump to the cam. It is a coupler that is made onto the pump. Mini/BMW does not recognize this as a problem and if you had this under warranty they would just tell you it is normal noise. It may very well never cause problems but it drove me nuts and I removed the pump and installed an electric vacuum pump. To be fair the coupler is very heavy duty and should hold up, but I just saw it as a distraction to all other possible harmful noises that may occur in the future. Otherwise I like a quiet as possible engine, well at least the "under the hood" part anyway. I think if you changed the pump eventually you would be back at the same noise level, but its never a bad thing to replace parts before they fail within reason.
I hope this helps.